In recent times, cosmetics have become developed beyond the concept of mere ornamentation for the face. Consumers now demand more from their makeup than simple color, coverage or moisturizing: it is now preferred that cosmetics provide some benefit to the skin, rather than just decorating it or making it feel softer. This consumer preference has resulted in the frequent use of biologically active ingredients in many cosmetic products. In view of the now well-recognized damaging effects of sun exposure on the skin, particularly favored active components are those which can counteract or prevent those effects. These components include, for example, sunscreens, antioxidants, and anti-wrinkle agents.
One of the primary difficulties in employing actives in a formulation is the potential instability of the active once incorporated. The very reason for their use in the formulation, i.e., their biological activity, means that they are not inert, and are therefore potentially subject to reduction or complete loss of potency if not combined with the proper vehicle. A number of routinely encountered factors can readily inactivate a biologically active compound in a formulation before it even reaches the consumer. Such factors include, for example, oxygen, extreme temperatures, UV light, water, and lipid peroxidases. It is particularly difficult to avoid the effects of oxygen and UV light, which are of course virtually ubiquitous in nature. Although degradation due to water can technically be avoided by anhydrous formulation, a water-containing formula is generally a preferred delivery system, as it provides hydration to the skin. Thus, there continues to be a need for development of a cosmetically acceptable vehicle which can deliver the hydrating benefits of water, yet will protect the actives contained in the vehicle from the degrading effects of environmental factors, including water, which rob them of their biological activity. The present invention provides a solution to this continuing problem.